Stan O'Neal of Merrill Lynch

Why: Following 3Q2007, Merrill revealed that it had lost $8 billion from subprime mortgages and had about $15 billion of questionable collateralized debt obligations. O'Neal stepped down about a week after the earnings announcement.

Peter Wuffli of UBS

When: July 2007

Why: Major losses at one of UBS' hedge funds that ultimately led to its closure and poor earnings in comparison to other banks were the main causes of his departure. His resignation came as a complete surprise for many.

Ken Thompson of Wachovia

AP

When: June 2008

Why: Thompson purchased the home lender Golden West financial in 2006 at the height of the housing bubble for $25 billion and made several other sub-prime and consumer investments that racked up multi-billion dollar losses. After serving for 32 years, Thompson was asked to retire as stock price continued to plummet.

Dick Fuld of Lehman Brothers

Why: Lehman filed for bankruptcy in September of 2008 with more than $600 billion in debt. The investment bank had been heavily leveraged and invested in the subprime mortgage business and held billions of dollars of toxic debt.

Kenichi Watanabe of Nomura

When: July 2012

Why: Financial regulators have been investigating insider trading allegations that Nomura had had been leaking information ahead of scheduled securities offerings. Nomura officials also said that there is a significant chance that other insider trading issues are investigated. The bank's earnings have also been weak.

Bob Diamond of Barclays

When: July 2012

Why: Barclays was fined ~$450 million by US and UK regulators after it was discovered that the bank had been manipulating interbank lending rates, specifically the LIBOR.